i2c: acpi: Introduce i2c_acpi_get_i2c_resource() helper

Besides current two users one more is coming. Definitely makes sense to
introduce a helper.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 8a88586..2728006 100644 (file)
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -45,6 +45,33 @@ struct i2c_acpi_lookup {
        u32 min_speed;
 };
 
+/**
+ * i2c_acpi_get_i2c_resource - Gets I2cSerialBus resource if type matches
+ * @ares:      ACPI resource
+ * @i2c:       Pointer to I2cSerialBus resource will be returned here
+ *
+ * Checks if the given ACPI resource is of type I2cSerialBus.
+ * In this case, returns a pointer to it to the caller.
+ *
+ * Returns true if resource type is of I2cSerialBus, otherwise false.
+ */
+bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
+                              struct acpi_resource_i2c_serialbus **i2c)
+{
+       struct acpi_resource_i2c_serialbus *sb;
+
+       if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+               return false;
+
+       sb = &ares->data.i2c_serial_bus;
+       if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
+               return false;
+
+       *i2c = sb;
+       return true;
+}
+EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource);
+
 static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
 {
        struct i2c_acpi_lookup *lookup = data;
@@ -52,11 +79,7 @@ static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
        struct acpi_resource_i2c_serialbus *sb;
        acpi_status status;
 
-       if (info->addr || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
-               return 1;
-
-       sb = &ares->data.i2c_serial_bus;
-       if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
+       if (info->addr || !i2c_acpi_get_i2c_resource(ares, &sb))
                return 1;
 
        if (lookup->index != -1 && lookup->n++ != lookup->index)
@@ -534,13 +557,7 @@ i2c_acpi_space_handler(u32 function, acpi_physical_address command,
                goto err;
        }
 
-       if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) {
-               ret = AE_BAD_PARAMETER;
-               goto err;
-       }
-
-       sb = &ares->data.i2c_serial_bus;
-       if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) {
+       if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
                ret = AE_BAD_PARAMETER;
                goto err;
        }

diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index ed80f14..6afc6e3 100644 (file)
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1054,6 +1054,17 @@ static inline int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
 }
 #endif
 
+#if defined(CONFIG_ACPI) && IS_ENABLED(CONFIG_I2C)
+bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
+                              struct acpi_resource_i2c_serialbus **i2c);
+#else
+static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
+                                            struct acpi_resource_i2c_serialbus **i2c)
+{
+       return false;
+}
+#endif
+
 /* Device properties */
 
 #ifdef CONFIG_ACPI